Expansion-drill



(No Model.) 2 Sheets-Sheet 1.

' G. E. BOWE.

EXPANSION DRILL.

Patented Aug. 12, 1890.

I I n I l v r II 1 v a I I I l I J l [MFA 2'02 Lsnce; 3 AttorneyWITNESSES I, a ct {No Model.) 2 Sheets-Sheet 2.

' G. E. BOWE EXPANSION DRILL.

Patented Aug. 12, 1890.

MAX 1 m M 02/ .7711 WESSES UNITED STATES PATENT OFFICE.

CLARENCE E. BOWVE, OF HURON, SOUTH DAKOTA.

EXPANSION-DRILL.

SPECIFICATION forming part of Letters Patent No. 434,241, dated August12, 18 90.

' Application filed April 24, 1890. Serial No. 349,383. (No model.)

' erence being had to the accompanying drawings, and to letters ofreference marked thereon, which form apart of this specification.

Figure 1 is a side elevation of my improved drill. Fig. 2 is a sectionalelevation thereof, one of the bits being removed by the section. Fig. 3is a view of the same, taken at right angles to the plane of theaforesaid figure. Fig. 4 is a bottom view of my invention, the

'bits being extended; and Fig. 5 is a modification thereof.

This invention relates to certain improvements in well-drills,particularly expansiondrills; and it consists in the construction andnovel combination of parts, as will appear from the followingdescription and accompanying drawings.

In the drawings, Ais the holder, which is not perfectly cylindric,having segments, as at a, removed from opposite sides, thus providingfor the upward passage alongside thereof of the Water through the well.The holder A is screw-threaded upon its inner surface to provide for itsready connection to the manipulating-rod. (Not shown.)

B B are the drills or bits, which are provided with cutting lips oredges 12, standing at right angles to the other portions of thelowerbeveled edge I), while their shanks b are let into the holder A,each being of a peculiar construction and .engaging a correspondinggroove 0 in said holder. The shanks Z2 are tapered toa pointattheirinner ends and have one edge convex, as at 5 extending to therightangled lower edges, while their opposite edges are concave, as at11 the greater portion thereof, the remaining portion being inclinedinward and downward, as at b. In each shank is a short curved slot bcorresponding to the curvature of the shank and receiving a cross-' pind in the holder A, limiting the movement of the bits or drills andretaining them in place therein. It will therefore be seen that when theholder with the bits or drills are in the pipe through which they workthey will not be extended or moved laterally; but after leaving saidpipe and coming in contact at their cutting-edges with the bottom of thehole or well said bits or drills will then be moved laterally as theycut their way through the earth or surface. This enlargement of thecutting of the earth or surface provides for the reception of not onlythe pipe, but also the coupling between the pipe-sections.

In the modification as disclosed in Fig. 5 the slots in the shanks ofthe bits or drills are extended, their extensions being provided withsprings e, bearing against the cross-pin d and the inner ends of saidslotextensions. Thus the drills or bits will normally press against thesides of the pipe, and consequently the moment they pass the lower endof said pipe be automatically expanded, the expansion being affected bythe action of said spring and not by contact of the bits or drills withthe earth or surface, as in the other case.

Having described this invention, What I claim, and desire to secure byLetters Patent, 1s-

1. In a well or boring auger, the holder provided with expansible bitsor drills the shanks of which are concave on one edge and convex on theother edge and provided with curved slots engaged by a cross-pin in saidholder, and springs arranged to act upon said bits or drills to expandthe same beyond the holder, substantially as set forth.

2. In a well or boring auger, the combination, with the holder, of thedrills or bits having the cutting lips or edges standing 'at rightangles to the other portion of the lower edge thereof and having theirshank portions

